ELECTRIC STORAGE DEVICE AND SECONDARY CELL

摘要

The present invention provides an electric storage device making it possible to prevent an excessive force from being applied to an electrode sheet. This electric storage device is provided with a case body having a plurality of lateral walls, and an electrode assembly accommodated in the case body. The electrode assembly has a multi-layered structure comprising a positive electrode sheet having an active material layer, a negative electrode sheet having an active material layer, and a separator interposed between the positive electrode sheet and negative electrode sheet. The case body includes at least one first inner wall surface perpendicular to the direction of stacking of the electrode assembly, at least one second inner wall surface adjacent to the first inner wall surface and parallel to the direction of stacking of the electrode assembly, and a corner surface linking the mutually adjacent first inner wall surface and second inner wall surface. A surface that passes through the boundary line between the first inner wall surface and the corner surface and faces the second inner wall surface is defined as a virtual boundary surface. An edge of the active material layer of the positive electrode sheet facing the second inner wall surface is positioned on the surface of the virtual boundary surface, or is positioned in a region spaced further apart from the second inner wall surface facing the edge than the position of the virtual boundary surface.